Li-Chun Chena, Yi-Ting Chenb, Jen-Jer Hsiehc, Zhao-Ming Liud, Jen-Ci Lina, Chung-Chao Lianga
a Department of Physical Medicine and Rehabilitation, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
b Division of Chest Medicine, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
c Division of Cardiology, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
d Pulmonary Function Test Laboratory, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
To investigate whether the use of beta-blockers (β-blockers) in patients with idiopathic hypertension compromises exercise performance.
Materials and Methods
Retrospectively, patients with well-controlled hypertension, who had received cardiopulmonary exercise testing (CPET) and pulmonary function testing, were consecutively enrolled. Their medical histories were reviewed. They were grouped into those receiving β-blockers and those receiving other antihypertensives. The heart rate (HR), blood pressure, oxygen consumption (View the MathML sourceO2), oxygen pulse, ventilatory anaerobic threshold, and respiratory exchange ratio were measured during CPET. The forced vital capacity and forced expiratory volume in 1 second were also collected from pulmonary function testing. Peak values of the CPET indices were compared between the two groups for each index separately by the Mann-Whitney U test. A p value less than 0.05 was considered statistically significant.
No significant differences were observed in basic characteristics, such as age (59 ± 9 years vs. 62 ± 9 years), and peak oxygen pulse (11 ± 3 vs. 11 ± 4), between the groups receiving β-blockers and other antihypertensives, respectively. Their resting systolic pressures were well controlled under antihypertensive medication (114 ± 13 mmHg vs. 118 ± 19 mmHg). A significantly lower maximal HR and maximal systolic blood pressure during peak exercise was observed in the β-blocker group compared with those in the other group (129.5 ± 17.0 beats/min vs. 146.1 ± 18.3 beats/min, p = 0.008, and 159.0 ± 22.2 mmHg vs. 172.6 ± 29.8 mmHg, p = 0.028, respectively). The exercise capacity of the β-blocker group was reduced, as shown by a lower measured peak View the MathML sourceO2/predicted peak View the MathML sourceO2 (View the MathML sourceO2%) (84.2% ± 9.6% vs. 96.2% ± 14.6%, p = 0.003) and a higher exercise heart rate reserve percentage (19.8% ± 10.3% vs. 7.8 ± 10.3%, p = 0.001).
The maximal HR, systolic blood pressure during peak exercise, and View the MathML sourceO2% were lower, whereas the exercise heart rate reserve percentage was greater in patients treated with β-blockers than in those taking other antihypertensives.
Beta-blocker; Cardiopulmonary exercise test; Hypertension; Peak oxygen consumption